Construction engineering foundation pit supporting steel formwork

The invention relates to a construction engineering foundation pit supporting steel formwork. The construction engineering foundation pit supporting steel formwork comprises rectangular steel frames which are symmetrically arranged front and back; propping-up mechanisms are arranged on the outer sides of the two rectangular steel frames; and a supporting mechanism is arranged on the outer side of a first concave steel frame. Through cooperation of two-way screw rods, lifting plates, round pins and leakage holes, the two lifting plates can drive the round pins to move downwards under the threaded driving of the screw rods and the guiding effect of guiding rods and are inserted into the corresponding leakage holes for limiting, and the situation that the rectangular steel frames displace under the effect of external force, propping-up is not firm, and construction is affected is prevented; and in addition, through the design of the leakage holes, waste water and soil can be discharged easily, and the situation